VB.net解析GPS数据应该用那种方法比较合适？

[lwj006]

在网上查找有事件触发方式和定时器查询的方式。
GPS输出的数据不是固定长度，是通过逗号来划分的。
GPS数据是每秒钟发送下面这么多数据的
大家有没有好的建议或者参考代码？

$GNRMC,045015.00,A,3109.73671,N,12124.75372,E,0.004,,141117,,,D*66
$GNVTG,,T,,M,0.004,N,0.007,K,D*3B
$GNGNS,045015.00,3109.73671,N,12124.75372,E,RR,15,0.72,5.8,9.7,1.0,0000*7F
$GNGGA,045015.00,3109.73671,N,12124.75372,E,4,12,0.72,5.8,M,9.7,M,1.0,0000*57
$GNGSA,A,3,02,05,13,15,20,21,29,30,,,,,1.35,0.72,1.15*13
$GNGSA,A,3,78,79,69,84,83,85,70,,,,,,1.35,0.72,1.15*18
$GPGSV,3,1,11,02,40,139,45,05,51,047,48,06,04,137,,07,01,034,*7F
$GPGSV,3,2,11,13,85,027,46,15,58,244,49,20,48,316,46,21,16,317,36*7A
$GPGSV,3,3,11,24,08,186,,29,40,256,49,30,19,055,41*45
$GLGSV,3,1,11,68,09,053,25,69,45,014,44,70,38,290,43,71,01,257,20*6F
$GLGSV,3,2,11,78,11,044,38,79,20,087,47,80,07,145,28,83,15,172,41*6B
$GLGSV,3,3,11,84,62,218,45,85,41,316,50,,,,51*6A
$GNGLL,3109.73671,N,12124.75372,E,045015.00,A,D*78
$GNGST,045015.00,6.9,,,,0.010,0.010,0.010*6C
$GNZDA,045015.00,14,11,2017,00,00*7C


另外还有一个问题请教：通过这条语句
Dim ports As String() = SerialPort.GetPortNames()
获得com号以后，这条语句
buf = SerialPort1.ReadExisting.ToString
是不是就不能用了？